Activist investor Jeff Smith and his Starboard Value have new significant positions in Jack in the Box Inc. (JACK) , Etsy Inc. (ETSY) and Macerich Inc. (MAC) , according to the fund's quarterly securities filing issued late Monday.

The likelihood that Starboard Value launches an M&A-focused campaign or some other type of insurgency at one of its new investments is pretty high. The New York-based insurgent fund has launched 138 campaigns at 110 different companies since 1999, including a jaw-dropping 62 director-election battles, according to FactSet Inc.

All three of the new investments are in companies that have other activist investors either quietly accumulating positions or already publicly pushing for changes.

TheStreet's sister publication The Deal in May reported that Jack in the Box could become an activist target after it announced that it was exploring options for its Qdoba Restaurant Corp. Mexican restaurant chain. Already insurgents Keith Meister of Corvex Management has accumulated a 1.8% position, about $56 million worth. In addition, the New York Post reported earlier this month that buyout shop Apollo Global Management, owner of Chuck E. Cheese, is close to acquiring the 720-location chain for as much as $500 million. Now, Starboard has accumulated about $18 million worth of Jack shares. Activists often push companies to spin off or sell businesses. They also often push for restaurant chains to franchise more locations, something an activist fund could agitate for at JACK. A move by Jack in the Box not to complete a Qdoba transaction likely would result in a Starboard or Corvex boardroom battle.

And on Tuesday, Jana Partners Barry Rosenstein, another prolific employer of boardroom war tactics, reported that he had accumulated a $134 million Jack in the Box position last quarter.